need intake port cc's for early Chrysler hemi 1954-58, anyone ??

I just cc'd early small port 1951-53 Chrysler 331 hemi heads, they have a 115 cc intake port

then I cc'd 1956 Chrysler 331 POLYSPHERE heads, they cc'd 150 cc's- BTW they use an identical intake manifold bolt layout, just a different port shape- I laid the poly intake gasket on hemi head, all bolts lined up

what I need to know is this- what's the intake port cc's of the "good" 1955 Chrysler hemi 331 "triple nickel" heads ?

and what's intake port cc's of the other big-port 1954-58 331/354/392 heads ?

I realize the 1955 are supposed to be the best of the bunch, but I want to see real port volume numbers- head port only, not intake manifold

I have a 1955 intake (331) and 1957 intake (392), the 1955 intake manifold ports do look a tiny bit larger, I didn't measure them yet. So I'm "guessing" the 1955 triple nickel intake ports are slightly larger than 392 heads as well

any help appreciated

 

Go to the hemi.com message board 331-354-392 section and ask Dan Miller, he works with Gene adams.I'm sure they could tell you the specs.
...John

 

I've been over there before, that board is kind of dead lately, but thanks for info

 

well I didnt' get an answer on this, after posting on 2 boards and asking a couple hemi gurus- I found good flow numbers on hemi heads, but no port volumes on stock heads

so I found out myself, by buying a pair of 1955 triple nickel Chrysler 331 hemi heads- they arrived today and I cc'd them

the 1955 "triple nickel" heads have 175 cc intake port volume

that's a pretty damned generous size intake port- for comparison, a standard Pontiac 400-428-455 4bbl engine 1967-72, rated anywhere from 300 to 390 HP in various forms/compression, only had 150-155 cc intake ports

the progression appears to have gone like this:

1951-53 hemi- 115 cc intake ports

1955-58 polysphere- 150 cc intake ports

1954-55 triple nickel hemi- 175 cc intake ports

I don't have info on 1956-58 hemi, but I do have a 392 hemi intake and 1955 hemi intake, and the 392 intake is visibly "slightly" smaller width/height ports than the 331 intake

as good as those triple nickel heads look, the real sleeper of the bunch is the polysphere heads- fully ported on a 354 block, w/392 crank- that should be one running SOB of an engine, and on the cheap

 

recently got intake manifolds for both 1955 and 1957 Chrysler hemis 331/392

the '55 intake ports look noticeably bigger to my eye, so I measured them up with dial caliper- here's the dimensions for you hemi fans

approx. dimensions measured at intake flange where port meets cylinder head:

1955 intake- 1.815" tall x 1.425" wide

1957 intake- 1.790" tall x 1.380" wide

the 1955 intake ports were .025" taller, and .045" wider

another thing- the 392 intake has a much larger cast in bottom exhaust heat crossover, and is noticeably heavier- quite a bit heavier.

 

I've got a set of heads from a CE55 (1955 Imperial 331) and another set from a NE57 (1957 New Yorker 392). Wish I'd seen this before and I would have gotten you intake runner volumes.

One thing that will affect them - considerably - is that the 392 head has a roughly 3/4" longer intake port due to Chrysler's insistance on using the "old" short-deck 331/354 intakes on the "new" raised deck 392. The intake port had to be built up to mate with the intake. That's also very likely the reason for the weight difference.

Keep that in mind when comparing runner volume between different makes. The runner lengths may be much different but share a similar volume. Usually the long skinny ports promote low RPM torque and the short fat ports are for high RPM power. "Generally."

Thanks for the info!

 

thanks for info

being all the intake manifolds interchange, the extra 3/4" length of the 392 port must be inside the 392 head, not in the intake

the exhaust crossover on bottom of intake, is noticeably larger, actually it's huge, compared to the 331 intake- that's where the weight is

it really is kind of an oddity, because rarely if never, does an engineer make a port smaller for an engine that is 61 CID larger, 331 to 392

perhaps the added length of the 392 head port makes the 45/55 and later heads nearly equal after all ? that added length has to add some cc's

do you have a 354 or 392 head, if so would you cc it and post results ?

 

Not sure why, but the 392 heads & ex seem to be squnched up a bit compared to the 55-56s. Yeah they added to the intake ports to match the earlier intakes. Thats why 392 heads seem to be more common & cheaper, they can only be used convieniently on 392s.

 

can the 392 heads intake flange be milled to use on a low-deck 331/354 ?

a combination of head milling to raise compression, and intake flange milling to align ports, may do it. Bolt holes may have to be redrilled/tapped.

In past we've milled heads .065" and intake flange of heads .025" on Pontiacs, to raise CR and achieve port alignment.

I realize it's not worth it is one already has the 54-56 331/354 heads, just wondering though. The 392 heads are the most plentiful and cheapest.